MyBatis多对多增删改查（不建关联实体）

时间 2019-11-12

标签 mybatis 多对增删关联实体栏目 MyBatis 繁體版

原文原文链接

MyBatis多对多增删改查（不建关联实体）

标签： mvc mybatis 增删改查

2015-06-04 21:11 2428人阅读评论(2) 收藏举报

分类：

web开发（7）

目录(?)[+]mysql

写在前面

本文的出发点在于：本人师傅比较NB，在项目中数据库操做用的MyBatis，须要涉及到多对多的操做，问师傅多对可能是否须要创建关联实体，师傅说了句“低级的能够建，高级的不须要”，因而乎，为了挑战难度，在项目中最终以不创建关联实体解决了多对多的操做问题。因而空闲的时间本身用spring-mvc 4、MyBatis 、MySQL 、Maven从零搭建起一个简单的demo，一是为了从头至尾巩固理解，二是为了留着之后忘记了能够查阅，三是也但愿能帮助到一些像我这样菜鸟级别的人。此片文章可能很是长，我写的步骤也算很细了，NB的人确定认为很累赘，不太重在分享！web

环境工具

操做系统：Windows 7

开发工具：Intellij IDEA 14

数据库链接：Navicat 11 Premium

接口测试：Postman

demo要完成的功能

对学生student的操做：学生学号必须惟一

添加学生信息；

修改学生信息；

按学号查询学生信息；

查询全部学生信息(不加载所选教师信息)；

查询全部学生信息(同时加载所选教师信息);

对教师teacher的操做：教师工号必须惟一

添加教师信息；

修改教师信息；

按工号查询教师信息；

查询全部教师信息(不加载所教学生信息)；

查询全部教师信息(同时加载所教学生信息);

对关联表student_teacher的操做：学生选授课教师

学生选择多个授课教师，关联信息插入关联表中

demo依赖jar包说明

junit-3.8.1.jar：用于单元测试；

spring-jdbc-4.1.6.RELEASE.jar：事务管理；

spring-webmvc-4.1.6.RELEASE.jar：spring-mvc 4必须；

spring-aspects-4.1.6.RELEASE.jar：面向切面编程；

mybatis-3.2.8.jar：MyBatis必须；

mybatis-spring-1.2.2.jar：MyBatis整合spring所需；

commons-dbcp-1.4.jar：数据库链接池；

slf4j-log4j12-1.7.7.jar：打印日志；

servlet-api-2.5.jar：servlet容器所需

fastjson-1.1.36.jar：json数据转换工具；

jackson-databind-2.3.3.jar：序列化类为json格式数据所需；

mysql-connector-java-5.1.32.jar：java链接MySQL数据库驱动包

开发步骤

第一步：新建数据库

1.ER图：
spring

2.student表：
sql

3.teacher表：
数据库

4.关联表student_teacher：
express

5.关联表增长外键与student和teacher关联：
apache

第二步：新建Maven工程

1.新建maven webapp工程：
编程

2.填写maven坐标：
json

3.新建完成的工程：

4.配置maven：
(1).maven home directory：maven解压后所在的路径；
(2).usere settings file:maven conf目录下的setting文件，具体配置略；
(3).local repository：本地maven仓库所在的目录，用于存放jar

第三步：搭建项目结构

新建entity包、dao包、service包、impl包、controller包，结构按需自定义

第四步：配置开发环境参数

修改项目编码：三处均为 “UTF-8”

第五步：增长全部jar依赖到pom.xml

添加项目所需的全部jar的maven坐标：

<dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>4.1.6.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>4.1.6.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aspects</artifactId> <version>4.1.6.RELEASE</version> </dependency> <!-- mybatis --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.2.8</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.2.2</version> </dependency> <dependency> <groupId>commons-dbcp</groupId> <artifactId>commons-dbcp</artifactId> <version>1.4</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.7.7</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> <scope>provided</scope> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.1.36</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.3.3</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.32</version> <scope>runtime</scope> </dependency> </dependencies>

第六步：配置application.development.properties和applicationContext.xml

application.development.properties：数据库链接参数以及数据库链接池参数；

#mysql database setting
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1/mybatis-demo?useUnicode=true&characterEncoding=utf-8
jdbc.username=user
jdbc.password=123456

#connection pool settings
jdbc.pool.minIdle=3
jdbc.pool.maxIdle=5
jdbc.pool.maxActive=15
jdbc.pool.maxWait=120000

2 . applicationContext.xml：spring容器核心配置

<?xml version="1.0" encoding="UTF-8"?> <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:p="http://www.springframework.org/schema/p" xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd" default-lazy-init="true"> <description>Spring公共配置</description> <!-- 该 BeanPostProcessor 将自动对标注 @Autowired 的 Bean 进行注入 --> <context:annotation-config/> <!-- 使用annotation 自动注册bean, 并保证@Required、@Autowired的属性被注入 --> <context:component-scan base-package="com.xiaolong.demo"/> <!-- MyBatis配置 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"/> <!-- 自动扫描entity目录, 省掉Configuration.xml里的手工配置 --> <property name="typeAliasesPackage" value="com.xiaolong.demo"/> <!-- 显式指定Mapper文件位置 --> <property name="mapperLocations" value="classpath:/mybatis/*Mapper.xml"/> </bean> <!-- 扫描basePackage下全部以@MyBatisRepository标识的 接口 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.xiaolong.demo.dao"/> <property name="annotationClass" value="com.xiaolong.demo.dao.MyBatisRepository"/> </bean> <!-- 使用annotation定义事务 --> <tx:annotation-driven proxy-target-class="true"/> <bean id="transactionManager" name="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource"> <ref bean="dataSource"/> </property> </bean> <tx:advice id="transactionAdvice" transaction-manager="transactionManager"> <!--<tx:attributes>--> <!--<tx:method name="*" propagation="REQUIRED" rollback-for="Exception"/>--> <!--</tx:attributes>--> </tx:advice> <aop:config proxy-target-class="true"> <aop:pointcut id="transactionPointcut" expression="execution(* com.xiaolong.demo.service.impl.*.*(..))"/> <aop:advisor pointcut-ref="transactionPointcut" advice-ref="transactionAdvice"/> </aop:config> <!-- local development环境 --> <beans profile="development"> <context:property-placeholder ignore-resource-not-found="true" location="classpath*:/application.development.properties"/> <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"> <property name="driverClassName" value="${jdbc.driver}"/> <property name="url" value="${jdbc.url}"/> <property name="username" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> <property name="maxActive"> <value>${jdbc.pool.maxActive}</value> </property> <property name="maxIdle"> <value>${jdbc.pool.maxIdle}</value> </property> <property name="minIdle"> <value>${jdbc.pool.minIdle}</value> </property> <property name="maxWait"> <value>${jdbc.pool.maxWait}</value> </property> </bean> <bean id="studentService" class="com.xiaolong.demo.service.impl.StudentServiceImpl" /> <bean id="teacherService" class="com.xiaolong.demo.service.impl.TeacherServiceImpl" /> </beans> </beans>

第七步：配置spring-mvc.xml

<?xml version="1.0" encoding="UTF-8"?> <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns="http://www.springframework.org/schema/beans" xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd"> <!-- 自动扫描且只扫描@Controller --> <context:component-scan base-package="com.xiaolong.demo" use-default-filters="false"> <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/> <context:include-filter type="annotation" expression="org.springframework.web.bind.annotation.ControllerAdvice"/> </context:component-scan> <!--<context:property-placeholder location="/WEB-INF/*.properties"/>--> <mvc:annotation-driven> <mvc:message-converters register-defaults="true"> <!-- 将StringHttpMessageConverter的默认编码设为UTF-8 --> <bean class="org.springframework.http.converter.StringHttpMessageConverter"> <constructor-arg value="UTF-8"/> </bean> </mvc:message-converters> </mvc:annotation-driven> </beans>

第七步：新建实体Student和Teacher

Student实体：

public class Student { private Integer id; //id private String name; //姓名 private String number; //学号,保证惟一 private String gender; //性别 private Integer age; //年龄 private List<Teacher> teachers; //授课老师集合 ..........省略get、set............ }

Teacher实体：

public class Teacher { private Integer id; //id private String name; //姓名 private String number; //工号,保证惟一 private String gender; //性别 private Integer age; //年龄 private List<Student> students; //所教学生集合 ............省略get、set方法..................... }

第八步：新建StudentMyBatisDao接口

在此以前须要先写个注解类MyBatisRepository

@Retention(RetentionPolicy.RUNTIME) @Target({ElementType.TYPE}) public @interface MyBatisRepository { }

而后新建StudentMyBatisDao接口

@MyBatisRepository public interface StudentMyBatisDao { int addStudent(Student student); int updateStudent(Student student); Student findStudentByNumber(String number); Student findStudentById(Long id); List<Student> findAll(); List<Student> findAllWithTeachers(); int selectTeachers(Long studentId, List<Long> teacherIds); }

第九步：编写MyBatis的StudentMapper.xml

说明：这里我使用了查询结果的继承关系，当不须要查询列表是resultMap就写studentMap，当须要将教师信息同时加载时返回的resultMap就是studentTeacherMap。另外，多对多在插入关联表的时候我使用的是批量插入，用了foreach，param2表明第二个集合参数

<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <!-- namespace必须指向Dao接口 --> <mapper namespace="com.xiaolong.demo.dao.StudentMyBatisDao"> <!--查询结果不包含app列表--> <resultMap id="studentMap" type="com.xiaolong.demo.entity.Student"> <id column="id" property="id" jdbcType="BIGINT"/> <result column="name" property="name" jdbcType="VARCHAR"/> <result column="number" property="number" jdbcType="VARCHAR"/> <result column="gender" property="gender" jdbcType="VARCHAR"/> <result column="age" property="age" jdbcType="INTEGER"/> </resultMap> <!--查询的时候将教师列表一块儿查询出来--> <resultMap id="studentTeacherMap" type="com.xiaolong.demo.entity.Student" extends="studentMap"> <collection property="teachers" ofType="com.xiaolong.demo.entity.Teacher"> <id property="id" column="t_id" jdbcType="BIGINT"/> <result property="name" column="t_name" jdbcType="VARCHAR"/> <result property="number" column="t_number" jdbcType="VARCHAR"/> <result property="gender" column="t_gender" jdbcType="VARCHAR"/> <result property="age" column="t_age" jdbcType="INTEGER"/> </collection> </resultMap> <sql id="columns"> id,name,number,gender,age </sql> <select id="findStudentByNumber" resultMap="studentMap" parameterType="java.lang.String"> SELECT <include refid="columns"/> FROM student WHERE number=#{0} </select> <select id="findStudentById" resultMap="studentTeacherMap" parameterType="java.lang.Long"> SELECT s.id,s.name,s.number,s.gender,s.age, t.id as t_id,t.name as t_name,t.number as t_number,t.gender as t_gender,t.age as t_age FROM student s LEFT JOIN student_teacher st ON s.id=st.s_id LEFT JOIN teacher t ON t.id=st.t_id WHERE s.id=#{0} </select> <select id="findAll" resultMap="studentMap"> SELECT * FROM student </select> <select id="findAllWithTeachers" resultMap="studentTeacherMap"> SELECT s.id,s.name,s.number,s.gender,s.age, t.id as t_id,t.name as t_name,t.number as t_number,t.gender as t_gender,t.age as t_age FROM student s LEFT JOIN student_teacher st ON s.id=st.s_id LEFT JOIN teacher t ON t.id=st.t_id </select> <insert id="addStudent" parameterType="com.xiaolong.demo.entity.Student"> insert into student ( name,number,gender,age ) values ( #{name,jdbcType=VARCHAR},#{number,jdbcType=VARCHAR},#{gender,jdbcType=VARCHAR},#{age,jdbcType=INTEGER} ) </insert> <update id="updateStudent" parameterType="com.xiaolong.demo.entity.Student"> update student <set> <if test="name != null"> name = #{name,jdbcType=VARCHAR}, </if> <if test="number != null"> number = #{number,jdbcType=VARCHAR}, </if> <if test="gender != null"> gender = #{gender,jdbcType=VARCHAR}, </if> <if test="age != null"> age = #{age,jdbcType=INTEGER}, </if> </set> where id=#{id,jdbcType=BIGINT} </update> <!--/*这种方式使用批量插入*/--> <insert id="selectTeachers"> INSERT INTO student_teacher (s_id,t_id) VALUES <foreach collection="param2" item="id" separator=","> (#{0}, #{id}) </foreach> </insert> </mapper>

第十步：编写StudentService接口

功能包括:对学生的增删改查以及学生选择教师

public interface StudentService { public void addStudent(Student student) throws Exception; public void updateStudent(Student student) throws Exception; public Student findStudentByNumber(String number); public List<Student> findAll(); public List<Student> findAllWithTeachers(); public void selectTeachers(Long studentId,List<Long> teacherIds)throws Exception; }

第十一步：编写StudentServiceImpl实现类

在添加和修改是我手动判断了学号是否重复

package com.xiaolong.demo.service.impl; import com.alibaba.fastjson.JSONObject; import com.xiaolong.demo.dao.StudentMyBatisDao; import com.xiaolong.demo.entity.Student; import com.xiaolong.demo.entity.Teacher; import com.xiaolong.demo.service.StudentService; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import org.springframework.transaction.annotation.Transactional; import java.util.List; /** * Created by xiaolong.zhu on 2015/6/4. */ @SuppressWarnings("ALL") @Transactional @Component public class StudentServiceImpl implements StudentService { private static final Logger logger = LoggerFactory.getLogger(StudentServiceImpl.class); @Autowired private StudentMyBatisDao studentMyBatisDao; @Override public void addStudent(Student student) throws Exception { logger.info("添加学生信息{}", JSONObject.toJSONString(student)); Student another = studentMyBatisDao.findStudentByNumber(student.getNumber()); if (another != null && another.getId() != student.getId()) throw new Exception("参数异常，number重复"); int result = studentMyBatisDao.addStudent(student); if (result != 1) throw new Exception("添加学生信息失败"); } @Override public void updateStudent(Student student) throws Exception { logger.info("修改学生信息{}", JSONObject.toJSONString(student)); if (student.getId() == null) throw new Exception("参数异常，id为null"); Student another = studentMyBatisDao.findStudentByNumber(student.getNumber()); if (another != null && another.getId() != student.getId()) throw new Exception("参数异常，number重复"); int result = studentMyBatisDao.updateStudent(student); if (result != 1) throw new Exception("修改学生信息失败"); } @Override public Student findStudentByNumber(String number) { logger.info("经过学号{}查询学生信息", number); Student student = studentMyBatisDao.findStudentByNumber(number); return student; } @Override public List<Student> findAll() { logger.info("查询全部学生信息"); return studentMyBatisDao.findAll(); } @Override public List<Student> findAllWithTeachers() { logger.info("查询全部学生信息及授课老师"); return studentMyBatisDao.findAllWithTeachers(); } @Override public void selectTeachers(Long studentId, List<Long> teacherIds) throws Exception { logger.info("学生{}选择授课老师{}", studentId, teacherIds.toArray()); Student student = studentMyBatisDao.findStudentById(studentId); for (Teacher teacher : student.getTeachers()) { if (teacher != null) { if (teacherIds.contains(teacher.getId())) throw new Exception("参数异常,该学生" + studentId + "已经选择了此教师" + teacher.getId() + "，不容许重复操做"); } } int result = studentMyBatisDao.selectTeachers(studentId, teacherIds); if (result != teacherIds.size()) throw new Exception("参数异常，教师id错误"); } }

在完成StudentServiceImpl以后，为了在Controller中能用@Autowired自动注入，须要将StudentServiceImpl在spring容器中注册，见applicationContext.xml

第十二步：编写StudentController类

说明：因为用的spring mvc 4，因此@ResponseBody就不用在写了，它已经写在了注解类@RestController中了。另外，ip是获取客户端真是ip，若使用了代理，就从header中取得，未使用代理，就使用request.getRemoteHost()获得。

package com.xiaolong.demo.controller; import com.alibaba.fastjson.JSONObject; import com.xiaolong.demo.entity.Student; import com.xiaolong.demo.service.StudentService; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.http.HttpStatus; import org.springframework.http.MediaType; import org.springframework.http.ResponseEntity; import org.springframework.web.bind.annotation.*; import javax.servlet.http.HttpServletRequest; import java.util.List; /** * Created by xiaolong.zhu on 2015/6/4. */ @SuppressWarnings("SpringJavaAutowiringInspection") @RestController @RequestMapping(value = "/demo/", consumes = {MediaType.ALL_VALUE}) public class StudentController { private static final Logger logger = LoggerFactory.getLogger(StudentController.class); @Autowired private StudentService studentService; @RequestMapping(value = "student", method = RequestMethod.POST, consumes = {MediaType.APPLICATION_JSON_VALUE}) public ResponseEntity addStudent(@RequestBody Student student, HttpServletRequest request) { String ip = request.getHeader("X-Forwarded-For"); if (ip == null) ip = request.getRemoteHost(); logger.info("ip {} 正添加新的学生信息{}", ip, JSONObject.toJSONString(student)); try { studentService.addStudent(student); return new ResponseEntity(null, HttpStatus.OK); } catch (Exception e) { e.printStackTrace(); logger.info(e.getMessage()); JSONObject error = new JSONObject(); error.put("error", e.getMessage()); return new ResponseEntity(error, HttpStatus.BAD_REQUEST); } } @RequestMapping(value = "student", method = RequestMethod.PUT, consumes = {MediaType.APPLICATION_JSON_VALUE}) public ResponseEntity updateStudent(@RequestBody Student student, HttpServletRequest request) { String ip = request.getHeader("X-Forwarded-For"); if (ip == null) ip = request.getRemoteHost(); logger.info("ip {} 正修改学生信息{}", ip, JSONObject.toJSONString(student)); try { studentService.updateStudent(student); return new ResponseEntity(null, HttpStatus.OK); } catch (Exception e) { e.printStackTrace(); logger.info(e.getMessage()); JSONObject error = new JSONObject(); error.put("error", e.getMessage()); return new ResponseEntity(error, HttpStatus.BAD_REQUEST); } } @RequestMapping(value = "student/{number}", method = RequestMethod.GET, produces = {MediaType.APPLICATION_JSON_VALUE}) public ResponseEntity findByNumber(@PathVariable("number") String number, HttpServletRequest request) { String ip = request.getHeader("X-Forwarded-For"); if (ip == null) ip = request.getRemoteHost(); logger.info("ip {} 正经过学号{}获取学生信息", ip, number); Student student = studentService.findStudentByNumber(number); return new ResponseEntity(student, HttpStatus.OK); } @RequestMapping(value = "students", method = RequestMethod.GET, produces = {MediaType.APPLICATION_JSON_VALUE}) public ResponseEntity findAll(HttpServletRequest request) { String ip = request.getHeader("X-Forwarded-For"); if (ip == null) ip = request.getRemoteHost(); logger.info("ip {} 获取全部学生信息", ip); List<Student> students = studentService.findAll(); return new ResponseEntity(students, HttpStatus.OK); } @RequestMapping(value = "students/teachers", method = RequestMethod.GET, produces = {MediaType.APPLICATION_JSON_VALUE}) public ResponseEntity findAllWithTeachers(HttpServletRequest request) { String ip = request.getHeader("X-Forwarded-For"); if (ip == null) ip = request.getRemoteHost(); logger.info("ip {} 获取全部学生信息以及其授课老师", ip); List<Student> students = studentService.findAllWithTeachers(); return new ResponseEntity(students, HttpStatus.OK); } @RequestMapping(value = "student/{id}/teachers", method = RequestMethod.POST, consumes = {MediaType.APPLICATION_JSON_VALUE}) public ResponseEntity selectTeachers(@PathVariable("id") Long studentId, @RequestBody JSONObject ids, HttpServletRequest request) { String ip = request.getHeader("X-Forwarded-For"); if (ip == null) ip = request.getRemoteHost(); logger.info("ip {} 学生{}选择授课老师{}",ip,studentId,ids.toJSONString()); try { studentService.selectTeachers(studentId, (List<Long>) ids.get("teacherIds")); return new ResponseEntity(null, HttpStatus.OK); }catch (Exception e) { e.printStackTrace(); logger.info(e.getMessage()); JSONObject error = new JSONObject(); error.put("error", e.getMessage()); return new ResponseEntity(error, HttpStatus.BAD_REQUEST); } } }

第十三步：测试Student操做的接口

全部接口集合：

1.测试添加学生信息：

2.测试修改学生信息：

3.测试按学号查询学生信息：

4.测试查询学生信息集合(不包含授课教师)：

5.测试查询学生信息集合(包含授课教师)：

6.测试学生选择教师(批量)：
若学生重复选择某一个教师，则不容许

成功选择教师

操做结果：

第十四步：新建TeacherMyBatisDao接口

同窗生部分

第十五步：编写MyBatis的TeacherMapper.xml

同窗生部分

第十六步：编写TeacherService接口

同窗生部分

第十七步：编写TeacherServiceImpl实现类

同窗生部分

第十八步：编写TeacherController类

同窗生部分

第十九步：测试Teacher操做的接口

同窗生部分

线上接口

demo部署在我服务器使用以下ip地址及端口号便可调用上述全部接口

敬请期待….